154 FAMILIES OF FLOWERING PLANTS 
Family Buxaceae. Box Family. This was formerly united with 
the Spurge Family above described, from which it may be distinguished 
by the absence of milky juice. There are 6 genera and 30 species; the 
familiar evergreen known as box is Buaus sempervirens, a member of 
the typical genus. In the Allegheny mountains grows a curious herb, 
the Allegheny mountain spurge (see Fig. 132), which also belongs to 
the family; the spikes of staminate flowers are quite fragrant. The 
only other known species of Pachysandra is Japanese, the genus thus 
affording another instance of that curious analogy between the Japan- 
ese and the eastern North American flora. 
Family Empetraceae. Crowberry Fam- 
ily. These are low, evergreen shrubs of 
heath-like aspect, with small axillary or clus- 
tered dioecious flowers succeeded by berry- 
like drupes. Sepals 3, petals 2 or 3 or want- 
ing; stamens usually 3. There are only 
three genera, Empetrum, Corema and Corrig- 
iola. High up in the arctic regions, extend- 
ing southward to our northern border, grows 
the crowberry (see Fig. 133), covering dense 
patches of ground, its black berries affording 
‘ an abundance of food for the Arctic birds. 
Another species is found in Antarctic South 
America. Scarcely less remarkable is the 
distribution of Corema, one species of which 
(C. Conradiz) occurs in a few isolated stations 
from Newfoundland to New Jersey, the other 
Fig. 133. The crowberry (Em- in southwestern Europe. The third member 
petrum nigrum). Original. . o se . . 
of this family, Corrigiola, is a monotypic 
genus of Florida. 
Family Coriariaceae. Coriaria Family. Consists of the single 
genus Coriaria, with 8 species, natives principally of the Old World, 
although one species occurs in Peru. They are shrubs with ribbed 
leaves and clusters of flowers having the parts in fives. The fruit con- 
sists of 5 one-seeded carpels, surrounded by the persistent fleshy petals. 
The fruit of the common European species (C. myrtifolia) is poisonous, 
but some of the Oriental forms have edible fruits, though the seeds are 
usually poisonous. 
Family Limnanthaceae. False Mermaid Family. These are deli- 
cate annual herbs of two genera. One, Limnanthes, is confined to the 
Pacific States, and contains about 6 species; the other, Floerkea, is a 
marsh plant rather widely distributed through the United States. The 
family is distinguished by the alternate, pinnately divided leaves, and 
